If a building suffers a catastrophic failure, pick up the phone and call your insurance company. From that moment on, they are in charge of a process that might take months or even years; easily enough time to bring the matter to a full council meeting for decisions to be made.
At the risk of telling granny how to suck eggs, have you had a full structural survey done? This will inform the renovate/remove/replace debate and provide a costed workplan. I hope you're not allowing members of the public into or near to this building in its current condition.
We're in the budget-setting season now, albeit a little late in the process, but if there is work to be done, it should be costed and included in next year's budget. Once this has happened, it could legitimately be delegated to an appropriate committee for action.